1. Field of the Invention
The present invention relates to a silver halide photographic material which has especially improved surface layer characteristics.
2. Description of the Prior Art
Commonly used photographic light-sensitive materials have at least one silver halide photographic emulsion layer on a support. The surface layer or the outermost layer of such materials is usually a light-insensitive surface-protecting layer coated on an emulsion layer, although in some exceptional cases the outermost layer thereof is a silver halide light-sensitive emulsion layer. When all emulsion layers are present only on one side of the support, the other side of the support is often provided with a light-insensitive backing layer. The above-mentioned surface layer or outermost layer, e.g., silver halide emulsion layer, a protecting layer and a backing layer, contains a hydrophilic colloid and/or hydrophobic polymer compounds as a binder.
When such photographic materials are put in an atmosphere of high humidity or high temperature, especially under the circumstances of high temperature and high humidity, the adhesiveness or tackiness of the surface thereof increases tends to cause the surface to adhere easily to another body in contact with this surface. Various disadvantages are often caused by this adhesive phenomenon which takes place between different parts of the surface of a photographic material, or between the surface of a photographic material and another surface when allowed to stand in contact with each other in the course of manufacturing a photographic material, taking a photograph, processing a photographic material, projecting film or storing the material. This tendency of such adhesive phenonmenon appears prominently when the surface layer of a photographic material contains hygroscopic or tacky compounds.
As a method for solving this problem, the so-called matt layer-making method is well known, wherein the presence of fine powders of an inorganic compound such as silica, barium sulfate, kaolin, calcium carbonate, etc., or presence of fine powders of an organic compound such as cellulose acetate propionate, polymethylmethacrylate, polystyrene, polytetrafluoroethylene, etc., are incorporated in the surface layer. The method causes the coaseness of the surface to increase and results in a decrease in the adhesiveness of the surface. However, this matt layer-making method is accompanied by a few undesirable side effects described below. Namely, (i) a homogeneously coated-layer can not be obtained because these fine powders easily aggregate in a coating solution, (ii) the photographic materials tend to be damaged and are more difficult to drive in a camera or projector than if fine powders of the above compounds were not present because of the decrease in slipping ability of the surface, (iii) the transparency of photographic materials after processings is reduced by the presence of fine powders of the above compounds, (iv) the granularity of an image is degraded by the presence of fine powders of the above compounds, and the like.
The conducting of another method wherein a surface active agent containing a perfluoroalkyl group, a wax or silicone is present in the surface layer in order to improve the slipping ability to result in a decreased adhesiveness is also accompanied by undesirable side effects of, for example, a reduction in an anti-static power of a photographic material to result in increased static marks, having adverse effects on the photographic characteristics, a decrease in transparency of the processed photographic material and the like.
Therefore, a new means of improving the adhesion resistance of photographic materials without the above-described deleterious side effects has been desired.